Posted on behalf of Ashley Yeager
To be or not to be; that always seems to be astronomical question—especially when it comes to being a planet.
Sadly, Pluto and its brethren are too small. Failed stars are too big. Now, some candidates might just be too dense. So it could up to Goldilocks to decide what’s “just right.” Or, at the very least, she might know whether COROT-exo-3b can be a part of the planet club.
Earlier this year, astronomers discovered the anomalous object with the French-Space-Agency-led COROT (COnvection ROtation and planetary Transits) satellite. Turns out the potential planet swings around its parent star—which is slightly larger and more massive than the sun—in a mere four days and six hours. Now, that’s by no mean an exoplanet record. But, add to that speed the fact that COROT-exo-3b is about the size of Jupiter yet is 21.6 times more massive, and then there’s a problem. The object is more than twice as dense as lead—a characteristic never seen before in planets, ESA reports in a press release.
If COROT-exo-3b is in fact a planet, it will be the most massive and the densest found to date. If Bad Astronomer Phil Plait were able to stand on its surface, he says he would weigh 4,200 kilograms, (although he doesn’t reveal how much he would weigh on Earth for comparison). Other details about COROT-exo-3b will appear in an upcoming issue of Astronomy and Astrophysics.
Scientists, however, are still debating whether to call this object a planet because it’s so unlike anything they’ve ever seen. They’ve tried considering COROT-exo-3b as a failed star—something too massive to be a planet but too weak to burn hydrogen and shine like a star—but it doesn’t quite fit in that class either.
COROT-exo-3b “might turn out to be a rare object found by sheer luck,” Francois Bouchy of the Institut d’Astrophysique de Paris told ESA. Or, the potential planet’s co-discoverer said, it might actually be a “member of a new-found family of very massive planets that encircle stars more massive than the sun.”
Bouchy added that based on the find astronomers are now starting to think that the more massive a star is, the more massive its planets might be.
Image: ESA